Airline shares dived on Monday in fright at the threat to traffic from an Icelandic volcanic ash cloud closing the skies over Europe, a year after European airlines were hit by month-long ash chaos.

Iceland’s Grimsvoetn volcano began erupting late on Saturday. Ash from the eruption is expected to reach Scotland on Tuesday, and might reach France and Spain on Thursday.

In April 2010 Iceland’s Eyjafjoell volcano erupted, spewing a massive cloud of ash that caused the planet’s biggest airspace shutdown since World War II with more than 100,000 flights cancelled and eight million passengers stranded.